Device for loosening and removing nuts overtight upon or adhering by corrosion to screwed members



April 16, 1957 p POTTER ETAL 2,788,689

DEVICE FOR LOOSENING AND REMOVING NUTS OVERTIGHT UPON OR ADHERING BYCORROSION TO SCREWED MEMBERS Filed May 17, 1955 *r gamma; H

:niiiiii iiii INVENTORS RICHARD P. POTTER 8- DAVID F. s. MELVILLE2,788,689 Patented Apr. 16, 1957 DEVICE FOR LOOSENING AND REMOVING NUTSOVERTIGHT UPON OR ADHERING BY CORRO- SION T SCREWED MEMBERS RichardPlews Potter, Kew, Victoria, and David Forsyth Shanks Melville, SouthYarra, Victoria, Australia, as signors to Inventions & PatentsProprietary Limited, Melbourne, Victoria, Australia Application May 17,1955, Serial No. 509,009 Claims priority, application Australia May 24,1954 8 Claims. (Cl. 81-523) This invention relates to a device forloosening and removing threaded fastening elements such as nuts, studs,setscrews and the li :e, which are over-tight upon or have becomeadherent by corrosion to complementary threaded elements and cannot beremoved by the use of spanners or wrenches in the normal way.

It is customary in practice to loosen or endeavour to loosen anovertight or firmly adhering nut, by striking a spanner applied to thenut or by the use of a punch or the like applied to the corners of thenut and struck with a hammer. Such methods even if effective are notsatisfactory in that the spanner or the nut or both are apt to bedamaged.

Now the principal object of this invention is to provide a simple,efficient and durable device which is convenient and easy to use, veryeffective for loosening an overtight or adhering nut or the like, andcan be manufactured at relatively low cost.

In achieving the above stated principal object and according to thebroadest concept of the invention, a device for loosening nuts overtightupon or adhering by c0rrosion to threaded members, comprises anut-loosening member engageable with a nut, an impulse member mountedupon and angularly movable about the nutloosening member, an abutment onthe nut-loosening member, a striking element on the impulse membernormally engaging the abutment, and resilient means connecting thenut-loosening member and the impulse member and retaining the latter ina normal position determined by engagement of the striking element withthe abutment, whereby upon angular movement of the impulse member thestriking element is separated from the abutment and the resilient meansenergised and upon release the impulse member is impulsively returned bythe energised resilient means to the normal position to cause thestriking element to strike the abutment and thereby actuate thenut-loosening member.

In a more specific construction a device for loosening and removingovertight or rusty adhering nuts comprises a socketcd shaft engageableat one end with a nut, a handgrip at the opposite end of the socketedshaft, a sleeve rotatably mounted upon the socketed shaft, a manuallyoperable arm extending radially from the sleeve, an abutment membersecured in and projecting from the socketed shaft, a striking membercarried by the sleeve and normally engaging the abutment member, and atleast one spring connecting the socketed shaft and the sleeve andretaining the latter and the manually operable arm in a normal positiondetermined by engagement of the striking member with the abutmentmember.

In using this more specific device, the sleeve is angularly rotated uponthe socketed shaft by the manually operable arm to move the strikingmember apart from the abutment and simultaneously energise the spring.

Upon release, the manually operable arm and sleeve are impulsivelyreturned by the energised spring to the normal position to cause thestriking member to strike the abutment and apply shock to the socketedshaft to loosen the nut.

The socketed shaft may be formed at each end to re ceive either anut-engaging socket or a handgrip, and the nut-engaging socket and thehandgrip may be positioned at required ends for loosening a nut havingeither a right or left hand thread. Moreover, by applying thenutengaging socket and the handgrip to appropriate ends the socketedshaft nuts having right or left hand threads may be tightened as will bereadily understood The invention will be more clearly understood fromthe description of the illustrative device for loosening and removingcorroded nuts depicted in the accompanying drawings.

in these drawings:

Fig. 1 is a perspective view of the illustrative device as assembled forremoval of a corroded nut or the like.

Fig. 2 is a perspective view of the illustrative device with certainparts removed.

Fig. 3 is a perspective view of the detachable handgrip of the deviceshown separately.

Fig. 4 is a View in perspective of a nubengaging socket shownseparately.

Fig. 5 is a view in perspective of an. extension piece connectable witha nut-engaging socket and engageable with the illustrative device.

Fig. 6 is an end elevation of the open. end of the nutengaging socketshown in Fig. 4, shown. on an enlarged scale.

Fig. 7 is a partly longitudinal section and side elevation of the deviceshown in engagement With a nut to be loosened and removed,

Fig. 8 is a transverse section on the line 8-8in Fig. 7.

Fig. 9 is a transverse section similar to Fig. 8 but showing certainparts in difierent positions.

Referring to these drawings in more detail, the numeral 5 designates theshaft of the device having an axial hole or bore 6 at each end.

Each axial hole comprises a square socket portion or mouth 7 to receivethe square shank it of a nut-engaging socket 9, and with a cylindricalextension 16 engageable by the shank 11 of a handgrip l2.

Rotatably mounted upon the shaft 5 at or about the midlength thereof isa sleeve or collar 13 having an integral radial bored socket 14 which isinternally threaded for threaded engagement of an arm 15 to which issecured a manually operable handle 16, whereby the sleeve 13 may berotated upon the shaft 5 for a purpose hereinafter described.

Formed centrally in the interior of the sleeve i3 is a peripheralchannel or groove 17 into which projects the tapered end 18 of a screw1? which is screwed into the internally threaded socket 14.

Fixed diametrically in the shaft 5 is a pin 20 which projects at theopposite ends into the channel 17 and by engagement therewith retainsthe sleeve 13 in the midlength position on the shaft 5. The pin 201 isfitted tightly in a diametrical aperture 21 in the shaft 5 and isinserted into the aperture through the axially bored socket 314. A hole22 is provided in the sleeve 13 in alignment with socket 14, and the pin20 upon insertion of an appropriate tool or punch through the hole 22may be driven from the aperture 21 outwardly through the socket 14 forreplacement as and when required.

The projecting ends 23 of the pin 21 are appropriately tapered forengagement by the tapered end 18 of the screw 19, see Fig. 8.

Mounted upon the shaft 5 and positioned on opposite sides of the sleeve13 are torsion springs 24, one end of each spring being bent to form aneye 25 whereby the spring is secured by a setscrew 25a to the shaft 5and the opposite end extended to comprise an arm 26 hav- I In use, andassuming that a nut 28 fast upon a stud 29, see Fig. 7, is to beloosened and the device is operated as follows:

A nut-engaging socket 9 of appropriate dimension to fit the nut 23 isdetachably connected to the shaft 5 by insertion of the shank 8 in thesocket 7, the socket 9 being retained in engagement by resilientpressure of a ball 30 urged upon a side of the socket 7 by a spring 31in a recess in the shank 8.

The shank 11 of the handgrip 12 is inserted in the cylindrical extensionof the axial bore at the opposite end of the shaft 57 Upon the devicebeing thus assembled and connected to the nut 28, the operator graspsthe handgrip 12 with one hand and the handle 16 with the other.

Holding the device by the handgrip 12 with the shaft 5 substantially inalignment with the axis of the nut 28 and stud 29, movement of thehandle 16 and arm angularly moves the sleeve 13 about the shaft 5 in thedirection of the arrow in Fig. 8, the shaft being held stationary byengagement of the socket 9 with the tight nut 28.

As the handle is thus moved, the end 18 of the screw 19 is angularlyseparated from the normal contact position with the end 23 of the pin20, and the springs 24 are further energised.

Upon the sleeve 13 being angularly moved to a sufficient extent aboutthe shaft 5, and the tapered end 18 of the screw 19 correspondinglyseparated from the tapered end 23 of the pin 20, the operator releasesthe handle 16, whereupon the energised springs 24 instantly return thearm 15 and sleeve 13 to the normal position, as indicated by the arrowin Fig. 9.

The quick return of the sleeve 13 to the normal position by the springs24 efiiects violent impact of the tapered end 18 upon the tapered end 23of the pin 20, the resultant shock being transmitted through the shaft 5and socket 9 to the nut 28 which is thereby loosened and may beunscrewed by further rotation of the handle 16 in the looseningdirection.

It will'be evident that the projecting end 18 of the screw 19 comprisesa striking element or member which upon return of the arm 15 and sleeve13 to the normal position strikes forcibly upon the projecting end 23forming a stop or abutment.

5 comprising a nut-loosening member engageable with a nut, an impulsemember mounted upon and angularly movable about the nut-looseningmember, an abutment on the nut-loosening member, a striking element onthe impulse member normally engaging the abutment, and resilient meansconnecting the nut-loosening member and the impulse member and retainingthe latter in a normal position determined by engagement of the strikingelement with the abutment, whereby upon angular movement of the impulsemember the striking element is separated from the abutment and theresilient means energised and upon release the impulse member is impulsively returned by the energised resilient means to the normalposition to cause the striking element to strike the abutment andthereby actuate the nut-loosening member.

2. A device for loosening and removing nuts overtight upon or adheringby corrosion to screwed members, comprising a socketed shaft engageableat one end with a nut, a handgrip at the opposite end of the socketedshaft, a sleeve rotatably mounted upon the socketed shaft, a manuallyoperable arm extending radially from the sleeve, an abutment membersecured in and projecting from the socketed shaft, a striking membercarried by the sleeve and normally engaging the abutment member, and atleast one spring connecting the socketed shaft and the sleeve andretaining the sleeve and the manually operable arm in a normal positiondetermined by engagement of the striking member with the abutmentmember, whereby upon angular rotational movement of the sleeve by themanually operable arm the striking member is moved apart from theabutment member and the spring is energised and upon release themanually operable arm As a result an implusive force or blow istransmitted J.

from the rapidly moving and relatively heavy handle 16 and arm 15 to theshaft 5 and thereby to the nut 28 which being gripped on all sides orfaces by the nutengaging socket 9 is loosened without damage.

The illustrative device is shown in Figs. 8 and 9, as it would be usedto loosen a nut having a right hand thread, but by transferring thenut-engaging socket 9 and handgrip 12 to the respective opposite ends ofthe shaft 5, the device may be used to tighten a nut having a right handthread or to loosen a nut having a left hand thread i as will be readilyunderstood.

It will be apparent that a range of nut-engaging sockets suitable fornuts of various sizes and having shanks 8 of standard size may be usedwith the device, and that relatively inaccessible nuts may be loosenedby the provision of an extension piece 32 having a shank 8 at one endand a socket 7 at the opposite as illustrated in Fig. 5 of the drawings.

We claim:

and sleeve are impulsively returned by the energised spring to thenormal position to effect impact of the striking member with theabutment and thereby apply shock to the socketed shaft.

3. A device as claimed in claim 2, wherein one end of the socketed shaftis formed to interchangeably hold nutengaging sockets of various sizesand the opposite end is formed to hold a handgrip.

4. A device as claimed in claim 2, wherein the sleeve is positioned atsubstantially the midlength of the socketed shaft and is provided ateach end with an axial bore having a mouth formed to interchangeably litthe standard shanks of nut-engaging sockets of various sizes and with aninward extension to receive a hand grip, whereby nuts having eitherright or left hand threads may be loosened or tightened.

5. A device as claimed in claim 2, having in the sleeve an internalperipheral groove, a diametrically disposed pin projecting from thesocketed shaft into the peripheral groove and retaining the sleeve uponsaid shaft, abutment members comprising the projecting ends of thediametrically disposed pin, and a screwsecured in the sleeve andprojecting inwardly'into the peripheral. groove and comprising thestriking member.

6. A device as claimed in claim 2, having a pair of springs positionedrespectively on opposite sides of the sleeve, each spring secured at oneend to the socketed shaft and at the opposite end to the manuallyoperable arm.

7. A device as claimed in claim 2, having helical springs of torsiontype disposed on opposite sides of the sleeve with the convolutionscoiled about the socketed shaft, an eye on one end of each spring, afastening extending through and securing the eye to the socketed shaft,and

a hooked arm extending from the opposite end of each 1. A device forloosening and removing nuts overtight upon or adhering by corrosion toscrewed members,

spring and engaging the manually operable arm.

8. A device as claimed in claim 2, having a handle of heavy materialsecured to the manually operable arm whereby the momentum of the latterin, the return movement and the impact of the striking member upon theabutment member are increased.

(References on following page) References Cited in the file of thispatent UNITED STATES PATENTS Douglass July 6, 1937 Robinson Sept. 23,1941 Pervier May 12, 1942 Aron et a1. Feb. 29, 1944 6 Craven Sept. 28,1948 Hambin Sept. 4, 1951 Disser Aug. 26, 1952 FOREIGN PATENTS GreatBritain Dec. 5, 1951

